The present invention generally relates to conversion of a lamp to touch control and, more particularly, to an electronic touch control light socket for conversion of ordinary lamps, such as a table lamp, to touch control which installs directly in the lamp in place of an ordinary light socket, and is "wireless" in the sense that the device eliminates all wiring related to touch control conversion.
Touch control lamps, both on/off and dimming types, have grown in popularity over the years, offering solid-state control of the lamp with a touch of the lamp's metallized body parts. Touch controls are quick and convenient, and especially ideal for pre-schoolers and physically disabled persons, such as arthritics, who find it difficult, in view of their limited dexterity, to operate conventional light switches.
One prior art approach for converting a table lamp to touch control, such as disclosed in U.S. Pat. No. 4,237,386 to Instance, is to package the touch control circuit in a separate, bulky module. The module can be applied to either a wall socket or mounted on the base of the lamp. Base mounting, however, embodies several disadvantages. It requires several wire connections to provide power to and from the module, as well as a connection to the lamp body to convey the lamp's touch signal to the touch-sensitive circuit. Moreover, these connections add assembly time to the lamp, and the wire splices used can be a hazard, particularly with all-metal lamp bodies. Furthermore, repair and replacement of the touch module can also be difficult and expensive, requiring disassembly or removal of the lamp base to gain access to the module. In addition, the modules' large size and wiring has often made installation in small lamps, solid-body lamps, and transparent lamps impractical or impossible due to lamp size or styling constraints.
A more recent approach for converting a table lamp to touch control has been to provide a touch control adapter which screws into the existing light socket, between the light bulb and its socket. Typically, a single clip-on wire or external spring is used to contact the shade support (harp) or outer surface of the light socket housing (shell) to couple the touch signal to the adapter's circuit. This approach is primarily intended for the do-it-yourselfer, whereby the user can convert existing table lamps to touch control use. However, adapters add inches to the height of the light bulb thereby interfering with many short-harp designs or globe shades which require the lamp's filament to be centered for even light distribution. Furthermore, the adapter's clip-on wire may be disturbed by unfamiliar users who attempt to turn on the lamp in a conventional manner. Lamp manufacturers view the adapter as an after-market add-on, not intended for lamp manufacturing use, which is expensive, i.e. adding the cost of male and female screw-in threads in addition to the cost of an already costly touch control circuit.
Consequently, a need still remains for a fresh approach to converting a lamp, such as an ordinary table lamp, to touch control. The objective of such an approach should be to avoid the drawbacks and shortcomings of the above-described prior art approaches without introducing new ones in their place. Also, such an approach should seek to have substantially universal applicability to all types of lamps and require minimal skill on the part of the installer in converting the lamp to touch control.